To date, we have results from preliminary experiments which show that knock-down of a critical IAP molecule using RNA interference techniques is capable of abrogating a barrier to cancer cell death in a previously significantly apoptosis-resistant human lung cancer cell line. As well, we have begun to explore a novel drug which inhibits the same IAP molecule pharmacologically and determine its efficacy in lung cancer cells. Early results appear to show that the pharmacologic drug is less effective than RNA interference techniques to diminish the IAP's actions to prevent cancer cell death. Further work is being conducted to delineate the mechanisms responsible for differential IAP expression in human lung cancer and also to define the mechanisms which can promote improved efficacy of currently available IAP inhibitor drugs.